Environmental Engineering Reference
In-Depth Information
10. unbiased, consistent;
11. summarizes impacts for use in EIS.
consistent and more effective in presenting information in the EIS, but their coverage of
impact significance, indirect impacts or alternatives is either very limited or non-existent.
The more complex models incorporate these aspects, but at the cost of immediacy.
4.9 Summary
The early stages of the EIA process are typified by several interacting steps. These
include deciding whether an EIA is needed at all (screening), consulting with the various
parties involved to produce an initial focus on some of the chief impacts (scoping), and
an outline of possible alternative approaches to the project, including alternative
locations, scales and processes. Scoping and the consideration of alternatives can greatly
improve the quality of the process. Early in the process an analyst will also wish to
understand the nature of the project concerned, and the environmental baseline conditions
in the likely affected area. Projects have several dimensions (e.g. purpose, physical
presence, processes and policies) over several stages in their life cycles; a consideration
of the environmental baseline also involves several dimensions. For both projects and the
affected environment, obtaining relevant data may present challenges.
Impact identification includes most of the activities already discussed. It usually
involves the use of impact identification methods, ranging from simple checklists and
matrices to complex computerized models and networks. In the UK, if any formal impact
identification methods are used, they are normally of a simpler type. The methods
discussed here have relevance also to the prediction, assessment, communication and
mitigation of environmental impacts, which are discussed in the next chapter.
Notes
1. This refers both to the spatial extent that will be covered and to the scale at which it is
covered. João (2002) suggests that the latter—which has been broadly ignored as an issue to
date—could be crucial enough to lead to different decisions depending on the scale chosen.
2. In the US, “agencies should: consider the option of doing nothing; consider alternatives
outside the remit of the agency; and consider achieving only a part of their objectives in
order to reduce impact”.
3. For instance, the EES's assumption that individual indicators of water quality (such as
dissolved oxygen at 31 points) are more important than employment opportunities and
housing put together (at 26 points) would certainly be challenged by large sectors of the
public.
4. Another category of techniques, simulation models, was not discussed because they are still
relatively undeveloped and have, to date, been applied only to problems involving a few
environmental impacts.
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